The main reason you should not use a petition preparer is because they are prohibited from providing legal advice. Once the case is filed, the preparer has no further involvement. Therefore your case is technically a pro se case. You will not know what to expect after your case is filed and you will not be adequately prepared for the meeting of creditors. Filing bankruptcy has serious legal consequences if not planned and filed appropriately.
It is common for the pro se debtor to lose assets that should have been protected had they used the advice of an attorney.
Further, many of these pro se cases are dismissed for technical errors. A dismissed case has the same impact on your credit as a completed case. Most people refile another bankruptcy case which results in two bankruptcy records on their credit. To make matters worse, (with filing fees) they would have spent less had they used a lawyer. It is better to get the case filed correctly the first time.
The United States Trustee recently filed a complaint against a non-attorney petition preparer for the negligent handling of a client’s case. The trustee cited the recent increase in pro se filings that have resulted from individuals using a petition preparer to file their case. In United States Trustee vs. Emmanuel Assaf Relief Agency, Case No. 10-40900-SBB, the U.S. Trustee filed a complaint for wrongful conduct and prior violation of the bankruptcy code. The U.S. Trustee is mainly concerned about the petition preparer’s unauthorized practice of law.